Pipe-threading machine



(No Model.) R. P. 82; L. B. CURTIS. PIPE THREADING MACHINE.

No. 477,296. Patented June 21, 1892.

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ATTORNEY WITNESSES:

5 2a., momuma, WASHINGTflN n c UNITED STATES PATENT OFFICE.

RODERICK P. CURTIS AND LEWIS B. CURTIS, OF SOUTIIPORT, ASSIGNORS TO CURTIS dz CURTIS, OF BRIDGEPORT, CONNECTICUT.

PIPE-TH READING MACHINE.

SPECIFICATION forming part of Letters Patent N 0. 477,296, dated June 21, 1892. Application filed July 30, 1891. Serial No. 401,207. (No model.)

To all whom it may concern.-

Be it known that we, RODERICK P. CURTIS and LEWIS B. CURTIS, citizens of the United States, residing at Southport, in the county of Fairfield and State of Connecticut,have in vented certain new and useful Improvements in Pipe-Threading Machines; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to certain new and useful improvements in pipe-threading machines, but especially does our invention have reference to devices for accurately locating the lead-blocks, whereby the latter will engage with the lead-screw carried by the dierlng.

In the accompanying drawings, Figure 1 is a vertical cross-section of a pipe-threading machine equipped with lead blocks constructed and adapted in accordance with our improvement; Fig. 2, a horizontal section of the same; Fig. 3, a horizontal section of the casing of a pipe-threading machine equipped with our device for locating the thumb-screws for the lead-blocks, and Fig. 4 a detail rear view of said device.

Similar numbers denote like parts in the several figures of the drawings.

Our invention is illustrated in connection with a pipe-threading machine made in substantial accordance with Letters Patent No. 363,626, issued May 24, 1887, to W. D. Forbes, said machine embodying in its structure a casing, a rotatory die-carrying ring supported within said casing and capable of a sliding movement therein, a lead-screw rigid with said ring, and a vise for clamping a pipe or golt during the operation of the threading- In machines of this description it has been found advisable to use a plurality of leadblocks, with which the lead-screw may engage, since in the instance of a single block there is more or less of a strain exerted laterally against the screw, whereas if two leadbloeks are used'and .placed opposite to each other such strain will not result. Two leadblocks have heretofore been used; but great dilficulty has been met with in properly loeating such blocks, because :the threads on each block must be adapted as anut to the lead-screw.

Our present invention locates the. position of the lead-blocks accurately and will be readily understood from the following description:

1 is the casing; 2, the die-carrying ring therein; 3, the lead-screw rigid with said ring,

and 4: a vise for clamping the pipe or bolt to be threaded.

5 are nipples cast on opposite sides of the casing and having fiat ends.

6 is a circular plate having a shoulder 7, adapted to fit snugly within the face of the casing, and 8 are arms opposite to each other and bolted to the outside edge of said plate at 9 and extending across the flat ends of the nipples 5. These arms have perforations 10 at points equidistant from the face of the plate 6. The plate and arms being in the position shown at Fig. 3, it will be readily understood that said perforations will serve as guides to locate the field of adrill, whereby the nipples may be pierced and interiorly th readed at points exactly opposite each other. The thumb-screws 11 are passed through the nipples thus pierced and threaded and are swiveled at 12 to the lead-blocks 13, which latter have elongated slots l4,'within which pins 15 extend from the casing 1 to afford means for properly guiding or steadying said blocks, as shown at Figs. 1 and 2. Of course more than two lead-blocks may be used, if desired; but two are all that are necessary.

16 is an annular seat within the casing and parallel with the face thereof. This seat is milled, so that its entire area is in the same vertical plane, and the lead-blocks are abutted against said seat, thereby causing the threads on said blocks to assume a relative position, the same as if they'were continuously cut on a single nut. are countersunk and the pins 15 are slightly enlarged at the outer ends and closely adapted to said countersunk portions, in order that said blocks may be firmly held against the seat 16.

It will thus be seen that the lead-blocks may be accurately located at any point in the casing as long as they are seated against the seat 16, and this is the most important fea- The outer walls of the slots 14. 1

ture of my invention, the accurate location of the screws 11 being adjunctive rather than essential.

By equipping the casing with the seat 16 v abutted against said seat, the pins'extended j from said seat Within said slots and'having heads which are closely adapted to said countersunk portions, and means, as thu nib-screws, for operating said blocks, substantially as shown and described.

3. In a pipe-threading machine, the combination,With the casinghavin g nipples on opposite sides thereof, of the plate having a shoulder which-fits snugly within the face of said casing, and arms secured to opposite sides of said plate and extended across said nipples, whereby the latter may be pierced in accurate alignment with each other to accommodate the thumb-screws for the lead-blocks, substantially as set forth. 1

In testimony whereof we affix our signatures ""in presence of two Witnesses.

RODERICK P. CURTIS. LEWIS n. onmrs. Vitnesses:

F. W. SMITH, Jr., J. S. FINOH. 

